Thus God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament; and it was so. (GENESIS 1:7)
Comets are icy objects in space that release dust or gas when they approach the sun. They are typically made of ice, dust, and frozen gases, and some even have a rocky core. Comets are very small compared to a planet and usually have highly elliptical (egg-shaped) orbits.
Some comets are called “sun-grazers.” They completely disintegrate when they get close to the sun; they may even crash right into it! When a comet nears the sun, it heats up and the gases and ice break off of the comet, making it smaller and leaving a beautiful trail of debris. This is where meteor showers come from. When the earth passes through the previous path of a comet, these pieces burn up as they fall into our atmosphere. This means that comets can’t last billions of years and this is a good confirmation that the solar system (including comets) is not that old.
The age of creation is based on the Bible’s genealogies. When we calculate the numbers in these genealogies, we get an age around 6,000 years (e.g., 4,000 years from creation to Christ). Comets make sense in a young solar system.